ADGRE1 and Arthritis: Increased synovial macrophage infiltration often leads to articular bone destruction.24 From RNA-sequencing analysis dataset GSE142607, we found that the tm4sf19 gene predominantly expresses in arthritis tissue-derived synovial macrophages (ADSM) (Fig. 1b).25 We confirmed that the expression of vcam1, was higher in fibroblast cells than macrophages and emr1, pan-macrophage marker, and tm4sf19 was higher in macrophages than fibroblast cells in both normal and CIA.